I have to ask whether it is worth playing through two more games for their story. Are their stories very good to go through the game two more times? I'm pretty tired of going through those dungeons and forests and junk, which is why I ask.

Well it sounds like you've finished Aoi route so you should have Arc, that makes the dungeons really quite fast to do (Although may leave you underleveled for the end boss). Kitty route imo was a bit disappointing after Aoi since it's about the same as first 2 (apart from harder end boss), Sheryl's route is similar to Aoi's but somewhat cooler, and longer. But by and large it's more of the same so if you're already tired of it maybe you should take a break from the game and get back to them later.

Phlebas the Phoenician, a fortnight dead, Forgot the cry of gulls, and the deep sea swell // And the profit and loss.
- - Gentile or Jew // O you who turn the wheel and look to windward, Consider Phlebas, who was once handsome and tall as you.
[T.S.Eliot: The Waste Land - IV. Death by Water]